// Problem: 
// Contest: 
// URL: 
// Memory Limit: 
// Time Limit: 
// #pragma GCC optimize("Ofast")
// #pragma GCC optimize("unroll-loops")
// #pragma GCC target("sse,sse2,sse3,ssse3,sse4,popcnt,abm,mmx,avx,avx2,tune=native")
#include<bits/stdc++.h>
using namespace std;
#define int long long
inline int read(){
	int s=0,w=1;
	char ch=getchar();
	while(ch<'0'||ch>'9'){if(ch=='-')w=-1;ch=getchar();}
	while(ch>='0'&&ch<='9') s=s*10+ch-'0',ch=getchar();
	return s*w;
}
signed main()
{
	int t;
	cin>>t;
	vector<int> v(35);
	v[1]=1;
	for(int i=2;i<=34;i++)
	{
		v[i]=v[i-1]*2;
	}
	while(t--)
	{
		int n;
		cin>>n;
		int i=1;
		while(v[i]<n)i++;
		//i--;
		if(n==v[i]||(n+1)==v[i])cout<<-1<<endl;
		else if(n==5)cout<<3<<endl;
		else 
		{
			//int x=n^(n-1),y=n^(n-(n-1)/2);
			if(n%2==0)cout<<n-1<<endl;
			else cout<<n-(n-1)/2<<endl;
		}
	}
	return 0;
}
